Enclosed concrete water reservoir supporting earthfill for multiple land uses

ABSTRACT

In one embodiment, the concrete post-tensioned multiple dome and integral beam roof modules, utilizing cable-tendons as they are assembled into a roof, form the roof of a concrete water reservoir. A comparative minimum amount of materials are used in this embodiment which is designed to be substantially completely surrounded by earth. The earth fill above is of sufficient depth for the creation of scenic and recreational park facilities, and other multiple uses and also the soil depths in many locations will support tree growth. In this reservoir embodiment, of the overall roof modules, the concrete water reservoir has a continuous floor, inclusive of footings, surrounding side walls, selectively spaced interior shear walls perpendicular to the side walls, spaced columns, either pre cast or formed in place, posttensioned valley beams integrally made in modules with integral domes and supported on the spaced columns, horizontal cable tendons used in the post-tensioning of the overall arrangement of the integral valley beam and dome modules, and expansion, cushion, and sealing materials to accommodate expansion and contraction of the concrete reservoir during temperature changes and surrounding earth movements. Each dome consists of four alike integral roof portions, each one curved throughout on a radius first determined in a geometric plane perpendicular to its respective post-tensioned valley beam at the center of the beam, resulting in single rather than compound curvature construction.

United States Patent [191 King et al.

[ 1 Dec.2, 1975 1 ENCLOSED CONCRETE WATER RESERVOIR SUPPORTING EARTHFILLFOR MULTIPLE LAND USES [76] Inventors: Jimmie D. King, 8316 Stone Ave.

North, Seattle, Wash. 98103; Harry R. Powell, 102 Maiden Lane East,Seattle, Wash. 98112 22 Filed: Nov. 1, 1973 211 Appl. No; 411,744

[52] US. Cl. 52/80; 52/169 DT; 52/167; 61/1 R [51] Int. Cl. EOZD 29/00[58] Field of Search 52/13, 14, 80,169, 167; 61/1 R [56] ReferencesCited UNITED STATES PATENTS 981,824 l/l911 Vcres 52/167 2,705,929 4/1955Atkins 52/73 3,283,515 11/1966 Pottorf 52/167 3,510,999 5/1970Habacher.. 52/169 3,638,377 2/1972 Caspe 52/167 FOREIGN PATENTS ORAPPLICATIONS 826,887 4/1938 France 52/169 362,473 12/1931 United Kingdom52/73 1,352,711 l/1964 France 52/73 328,442 10/l923 Germany 52/167456,060 2/1928 Germany 52/169 380,041 4/1940 Italy 52/169 PrimaryExaminerErneSt R. Purser Assistant Examiner-Henry Raduazo Attorney,Agent, or FirmRoy E. Mattern, Jr.

[57] ABSTRACT In one embodiment, the concrete post-tensioned multipledome and integral beam roof modules, utilizing cable-tendons as they areassembled into a roof, form the roof of a concrete water reservoir. Acomparative minimum amount of materials are used in this embodimentwhich is designed to be substantially completely surrounded by earth.The earth fill above is of sufficient depth for the creation of scenicand recreational park facilities, and other multiple uses and also thesoil depths in many locations will support tree growth. In thisreservoir embodiment, of the overall roof modules, the concrete waterreservoir has a continuous floor, inclusive of footings, surroundingside walls, selectively spaced interior shear walls perpendicular to theside walls, spaced columns, either pre cast or formed in place,post-tensioned valley beams integrally madein modules with integraldomes and supported on the spaced columns, horizontal cable tendons usedin the post-tensioning of the overall arrangement of the integral valleybeam and dome modules, and expansion, cushion, and sealing materials toaccommodate expansion and contraction of the concrete reservoir duringtemperature changes and surrounding earth movements. Each dome consistsof four alike integral roof portions, each one curved throughout on aradius first determined in a geometric plane perpendicular to itsrespective post-tensioned valley beam at the center of the beam,resulting in single rather than compound curvature construction.

12 Claims, 14 Drawing Figures US. Patent Dec. 2, 1975 Sheet 1 of 53,922,823

US. Patent Dec. 2, 1975 Sheet4 0f5 3,922,823

ENCLOSED CONCRETE WATER RESERVOIR SUPPORTING EARTHFILL FOR MULTIPLE LANDUSES BACKGROUND OF THE INVENTION In particular reference to enclosedwater reservoirs, in the past they have been made of wood assemblies ofmultiple timbers and sheets of plywood; steel assemblies of spacedframes; trusses, and beams; concrete assemblies of prestressed concreteunits; hyperbolic paraboloid shells; and/or cast in place concreteslabs; and selective combinations of portions of these assemblies. Allof these past construction assemblies have served well in meeting thedesign objectives of the past. However, current design objectives,especially entering on the requirements of multiple land use anduncontaminated water supplies in urban areas, have indicated the pastassemblies of enclosed water reservoirs do not meet the currentobjectives, such as: insure the quality of immediately available freshwater for domestic human supply against bacterial and chemicalcontamination, algae growth, and vandalism; construct the enclosedreservoir of permanent materials; construct the enclosed water reservoirat minimum cost; maintain and operate the enclosed water reservoir atminimum expense; and use the area above the enclosed water reservoir ofmultiple purposes such as for scenic and recreational parks,playgrounds, outdoor theaters, reflecting pools, etc. In reference toother buildings, such as garages, treatment plants, etc. many of thesame advantages involving multiple use will be realized when theconcrete post-tensioned multiple dome and integral beam roof modules areassembled as a roof utilizing the post-tensioned cable-tendons.

SUMMARY OF THE INVENTION Concrete post-tensioned multiple dome andintegral beam roof modules utilizing cable-tendons, when assembled as anoverall roof, may be effectively used as a roof for many multiple usestructures. For example, a fully enclosed concrete water reservoir,providing areas above for multiple purposes such as for scenic andrecreational parks, is uniquely constructed, especially in respect tousing these integral valley beam and dome modules. In each of the valleybeams of a dome module, a conduit is formed in a parabolic drapeconfiguration, with the high points of the conduit being located at theends of each valley beam over its column supports, and the low point ofthe conduit being located at the midspan of each valley beam. Uponsubsequent jacking or pulling of the cable-tendons within their conduitsand securing them, all the valley beam and dome modules arepost-tensioned in their original pattern. As a consequence, throughoutthis overall roof, such as the roof of a concrete water reservoir, thecompression forces in the concrete are essentially multi-directional,the bending moments in the valley beams are reduced and also the tensionstresses in the comparatively thin shell domes are well reduced belowthe cracking stress of concrete in tension. In this way a lighteroverall concrete water reservoir structure and other multiple usestructures are efficiently constructed.

The collective contours of the domes, wherein each dome has four alikeintegral roof portions, each being of a single rather than of a compoundcurvature construction, reduces costs of manufacture while maintaininghigh strength capabilities. Also the overall contours of the domes formthe top of the reservoir so the maximum depths of earth fill, used ingrowing trees, are located over the valley beam and column loadtransferring locations, and the minimum depths of earth fill, used ingrowing grass or other small vegetation are located over the centralportions of the domes, again maximizing the overall structuralefficiency of the multiple land use water reservoir. The effectiveincorporation of both resilient expansion and sealing materials with theconcrete and the effective coating of the concrete surfaces withcrystallization type waterproofing, complete the construction of thewater confining overall cement reservoir to store water during a longlife while at all times protecting the water from bacterial and chemicalcontamination, algae growth, and/or vandalism.

DRAWINGS OF A PREFERRED EMBODIMENT A preferred embodiment of assembledconcrete posttensioned multiple dome and integral beam roof modulesserving as a roof of a concrete water reservoir, over which earth isfilled to create an area above for other uses, such as for a scenic andrecreational park, is illustrated in the drawings, wherein:

FIG. 1 is a perspective view, with portions removed for illustration, ofthis post-tensioned roof on a concrete water reservoir, fully installedand covered with earth fill supporting in turn scenic and recreationalpark facilities, such as the illustrated tennis courts;

FIG. 2 is a partial sectional view of the concrete water reservoirillustrating the underground water storage and the above ground scenicand recreational park facilities;

FIG. 3 is a top view with portions broken away at different levels toillustrate how the concrete water reservoir is constructed utilizingmodules wherever possible and arranging them for orthogonalpost-tensioning insuring multi-directional compression in the concretemembers providing continuity over multiple spans and thereby increasingtheir collective overall load carrying capacity;

FIG. 4 is a partial schematic section view indicating on a larger scalethe overall curvature of the top of the concrete water reservoir, toprovide drainage for the earth fill;

FIG. 5 is a top view, before filling with earth, of a concrete waterreservoir, indicating how the modules may be arranged to provide anoverall free form water reservoir, in contrast to the square orrectangular water reservoir;

FIG. 6 is an enlarged top view of a dome and valley beam module withone-quarter of the dome being lined for emphasis of the utilization offour alike quarters, each quarter being formed as a single rather than acompound curve structure, and also being lined as a reference key for acomputer output;

FIG. 7 is an enlarged top view of one-quarter of a dome and valley beammodule on which a tension and compression computer output is plotted;

FIGS. 8, 9 and 10 schematically illustrate, respectively, how thepost-tensioning occurs in vertical .geometric planes, as shown in FIG.8, using the cabletendons draped through valley beam conduits, aroundall of four sides of an integral valley beam and dome module, as shownin FIG. 9, with a modification occurring wherein the post tensioningoccurs in a horizontal geometric plane in the valley beams located overthe side walls of the concrete water reservoir, as shown in FIG.

FIGS. 11 and 12 in enlarged sides, with some portions removed forillustrative purposes, show how the integral valley beam and domemodules are formed, how they are positioned on the columns, and how the.conduits and the cable-tendons are located;

FIG. 13 is an enlarged partial view, essentially in cross-section,illustrating how an end of a cable-tendon is secured at the terminus ofa conduit extending through a valley beam; and

FIG. 14 is an enlarged partial view essentially in cross-section, ofportions of the concrete water reservoir to illustrate the transitionfrom the central construction components to the side constructioncomponents where shear loads are handled and where expansion andcontraction forces are accommodated.

DESCRIPTION OF PREFERRED EMBODIMENT IN A RESERVOIR Multiple Use ofGround Area Above Reservoir The preferred embodiment of the concretewater reservoir 20, illustrated in the drawings, allows the potentialmultiple ground use area above the reservoir, after filling with earth22, for small children play areas 24, playfields for games 26, picnicspots, outdoor concert and show theaters, and scenically landscapedparklike surroundings inclusive of lawns 28, gardens, trees, 30, ponds32, and streams, as particularly shown, in part, in FIGS. 1 and 2.

Principal Design Criteria for This Water Reservoir The principalobjectives or design criteria for this water reservoir were to arrangefor the multiple use of the area above the reservoir, yet do so atminimum cost, constructing the water reservoir 20 of permanently lastingmaterials, and at all times never deviating from the major objective orpurpose of insuring the availability of quality of fresh water, fullyprotected from bacterial and chemical contamination, algae growth, andattempts of vandalism.

Highlights of the Specific Design Approach Concrete, reinforced wherenecessary, is used because it is compatible with water environment,suitable for underground construction, readily conformed to a desiredshape, easily waterproofed using a crystallization waterproofing,durable and thereby leading to a long operational life, and purchased,handled, and formed at a comparative moderate cost level. Futhermore,reinforced thin shell concrete technology is followed wherein minimalmaterials are required to gain the required strengths to withstand thedirect compression stresses. Moreover, modular concrete unitconstruction and assembly is employed. In the modular units cabletendonsare arranged and tightened following orthogonal post tensioningprocedures to acquire multi-directional compression in concrete andthereby increase the load carrying capacity of the overall concretewater reservoir structure 20.

Multiple Integral Valley Beam and Dome Modules Serving as the IntegratedWater Reservoir Roof The selection of concrete, followed by theutilization of thin shell concrete technology, and the adoption of posttensioned modular reinforced concrete unit construction, leads to theunique creation of integral valley beam and dome modules 40 servingtogether as the integrated water reservoir roof 42 shown in FIGS. 1, 2,3, and 14. They excellently carry direct compression stresses and do sowhile utilizing a comparative minimal amount of materials. They arecompatible with rectangular grid arrangements and yet collectively maybe arranged not only in overall square and rectangular roof areas, butalso in free form areas, which are subdivided in various gridarrangements, as viewed in FIGS. 3 and 5. Their overall curved portionsare, in effect, made of four curved portions 44, as shown in FIGS. 9, ll and 12, each one of which is made in a single rather than a compoundcurvature form, making their forming during their manufacture reasonablyeasy in conjunction with their integral valley beams 46. Moreover, theproduction forms, not shown, into which the concrete is poured may beused many times to produce a large number of integral valley beams anddome modules 44) at or for one job site, and oftentimes the productionforms may be utilized at or for another job site where another enclosedconcrete water reservoir 26) is to be constructed.

Principal Order of the Overall Production of the Water ReservoirFollowing excavation and the arrangement of forms, then as viewed inFIGS. 2, 3 and 14, the concrete footings 52 are poured; the floor 54 ispoured or optionally poured later; the preformed columns 56, 58 withsteel reinforcing 59 are positioned; the shear walls 60 are poured; thepreformed valley beam and dome modules 40 are positioned using theirgroove 48 and projection 50 interfitting structures; the cable-tendons62 are installed in conduits 64, then post-tensioned, and secured upontightening an assembly 65 of a nut 66, threaded clamping sleeve 68 andend plate 70, as shown in FIGS. 12 and 13; as necessary, roof drains 72are installed; water piping including overflow lines 74 are installed;access doors, not shown, are installed; then perimeter walls with steelreenforcement 81 are poured; and timely during this overallconstruction, expansion spaces 82 are maintained, seals 84 and 86 areinstalled, elastomer shock pad assemblies 88 are positioned,waterproofing materials are utilized, and necessary connectors andfasteners are tightened. Finally after the concrete has curedsufficiently, earth backfilling and earth top filling 22 is undertaken,followed by creating the improvements above the reservoir 20, such aslandscaped parks and recreational facilities.

Integral Valley Beams and Dome Modules The integral valley beams anddome modules are produced using thin concrete shell production methodsand may be produced almost in place as special forms, not shown, aremade to be moved over completed integral valley beams and dome modules40. As illustrated in FIG. 11, the curved quarters 44 of the module 40are each made of single rather compound curves. Conventional steelreinforcement 45 is utilized as necessary. Their outside surface radius92 remains constant, and both radii 92, 94 may be taken from the samestarting line 96, which parallels the respective valley beam 46 andpasses below the center 98 of the module 40. Throughout most of the roof42 of the water reservoir 20, the integral valley beams and dome modules40 are made alike in this way. Around the edges of the reservoir 20,they may be changed.

Changes in Design of Integral Valley Beams and Dome Modules Around theEdges of the Reservoir to Interfit with the Shear Walls As shown inFIGS. 2, 3, and 14, the designs of components, previously noted assuitable when used in central portion of the water reservoir 20, must bemodified around the edges of the reservoir 20. Expansion movements ofthe reservoir caused by temperature changes, possible earth movements,and general sound structural design, requires the inclusion of shearwalls 60, the provision of expansion spaces 82, sealing materials 84,86, and cushioning materials, such as the elastomer shock pads 88.

To make the shear walls 60 effective and yet allow for some movementbetween them and the modified integral valley beam and dome module 100,located above, each shear wall 60 along its top portion is formed withshear keys leaving spaces 102 and structures 104 inbetween them. Alsothe bottom portion of the modified valley beam 106 above is formed withcomplementary interfitting keys with structures 108 and spaces 1 10. Theoverall fit between the shear wall 60 and the modified module 100 allowstheir independent relative movement through the limited overall spaces82. Throughout this spacing, elastomer shock pads 88 are placed toserve: a cushioning effect, and an earthquake load transferring effect,between the shear walls 60 and modified valley beams 106 of the roof 42.

Elastomer Bearing Cushion Pads Serving as Pocket Bearings in theMounting of Columns Used Nearer the Edges of the Reservoir In additionto the shear wall structural accommodations made at selected positionsalong the edges of the reservoir 20, other accommodations in regard tothe columns 58 are undertaken, so overall movements of the resevoir 20may be satisfactorily compensated for, without damage occurring to anyof the overall components of the reservoir 20. As illustrated in FIG.14, columns 58 are generally shorter than columns 56, as the bottom ofthe reservoir has sloped portions 112 at this locale. Below, footing 53is formed with a hole 113 to receive a bottom pocket bearing assembly114 having a bottom elastomer pad 116 and a premolded joint fillersleeve 118, of an elastomeric material which together surround thebottom of the erected column 58. Above, the valley beams 106 and 46 areformed to create a flange 122 to receive a top pocket bearing assembly124 having a top elastomer pad 126 and a premolded joint filler ring 128of an elastomeric material, which together surround the top of theerected column 58. The longer columns 56 because of their length andalso their greater distance from the side walls are able to selfcompensate for expansive and contractive movements of the overallreservoir 20. However, if an entire reservoir of another embodiment wereto be made of shallower depth, all columns might be cushioned in someway.

Positioning of the Conduits and Cable-Tendons to Create the MostEffective Post-Tensioning of the Reservoir Roof Composed of the MultipleIntegral Valley Beams and Dome Modules As indicated in FIGS. 8, 11, 12and 14, conduits 64 are preformed in a parabolic drape configurationwith their highest elevation being located over the supporting columnsand their lowest points being located at the midspan of each valley beam46, 106 in which these conduits 64 are permanently embedded upon thecuring of surrounding poured in concrete. During assembly of the overallreservoir 20, cable-tendons 62 are threaded through these conduits 64 inthe overall orthogonal pattern. After the pre-assembly of all thereservoir 20, these cable-tendons 62 are jacked or other wise tensionedand then secured with the fastening assembly 65, as illustrated in FIG.13, to complete the final structural assembly of the reservoir 20.

The effectiveness of this post-tensioning is schematically illustratedin FIG. 8 with the force vectors, as it occurs throughout most of thereservoir 20. Along the sides of the reservoir, this post-tensioning isundertaken in a horizontal geometrical plane, as shown in FIG. 10,rather than in the vertical geometrical plane, as shown in FIG. 8.

Plot of Computer Output in the Analysis of the Total Load Condition Ofthe Reservoir, With Respect to a Quarter of a Dome Structure of AnInstalled Valley Beams and Dome Module Serving with Others as the Roofof the Reservoir In FIG. 7, in reference to the key location set forthin FIG. 6, a." quarter 44 of a dome structure of an installed integralvalley beams and dome module 40 is illustrated in a plot of a computeroutput indicating the analysis, under total load conditions of theoverall reservoir 20, of the distribution of tension and compressionstresses. The vectors, both long and short, cross other vectors at rightangles to indicate the direction of the stresses. Plain line vectors,both long and short are plotted compression vectors, and lines, bothlong and short, terminating with dotted ends, are plotted tensionvectors. Therefore the desirable overall objective of having theconcrete undergoing the most favorable compression and tension isclearly indicated. In some embodiments, tension stresses may beeliminated in the concrete domes.

Other Uses for All or Many of the Components of the Water Reservoir AsThey Could be'Made, Erected, and Used for Other Purpose StructuresAlthough the illustrated and described preferred embodiment of thepost-tensioned assembly of the roof modules has centered on an enclosedwater reservoir, the post-tensioned dome roof structure composed of itsmany unique modules could be supported as a roof for other structureshaving a different operational purpose. For example, garages, coveredmarinas, open market places, dwellings, sewage plants, etc. could beconstructed using the integral valley-beams and dome modules which arepost-tensioned in the orthogonal pattern. Throughout all such structuresthe efficient utilization of a minimum quantity of long lastingmaterials will likewise be realized. Throughout all the methods, themost efficient procedures and/or order of steps will be undertaken. Forexample, the columns may be formed and poured in place using continuoussteel reinforcing rods or they may be precast and movedinto place usingconnectors and fasteners for their securement and tie in with their selfcontained steel reinforcing rods.

Preferably and especially in reference to water reservoirs, the slope ofthe side walls will be essentially perpendicular to the diagonalresultant vector force determined by first calculating the horizontalvector of a potential earthquake force in one direction, to be handledat shear walls on one side of'the reservoir and then by calculating thevertical vector force determined by the dead load of the roof structure,and thereafter calculating their resultant. It is to be noted the shearwalls on the other side of the reservoir will handle the horizontalvector of a potential earthquake force in the other direction.

In addition to standing ready to handle earthquake loads, the shearwalls and their shear keys and the complementary shear keys of thevalley beams, with other compensating structural arrangements compensatefor: movement during temperature changes, elastic shortening due topost-tensioning, movement or creep upon post-tensioning, and theshrinking in concrete upon curing.

As necessary, the multiple use concepts of the overhead areas may bealways considered and preferably undertaken. However, the domes may beleft exposed for all time or until a suitable multiple use is decidedupon.

We claim:

1. An enclosed concrete water reservoir, utilizing a comparative minimumamount of materials, designed to be substantially completely surroundedby earth, the earth above being of sufficient depth for the creation ofscenic and recreational park facilities, inclusive of soil supportingtree growth, comprising:

a. a continuous floor inclusive of footings;

' b. surrounding side walls;

c. spaced columns positioned over the footings;

' d. post-tensioned valley beams integrally made in molules withintegral domes and supported on the spaced columns;

e. horizontal cable tendons used in the posttensioning of the overallarrangement of the integral valley beam and dome molules; and

f. selectively spaced interior shear walls arranged perpendicular to thesurrounding side walls having components of shear key structures alongtheir tops, and wherein the post-tensioned valley beams integrally madein modules with the integral domes, where such valley beams are locatedover the interior shear walls, have components of shear key structuresalong their bottoms which complementary, with slight spacing, otherwiseinterfit with the shear key structures of the interior shear walls; g.compressible sealing materials installed between adjacent concretecomponents of the reservoir to accommodate expansion and contraction ofthe enclosed concrete reservoir during both temperature changes andsurrounding earth movements, to thereby seal and keep sealed theinterfaces between adjacent concrete components.

2. An enclosed concrete water reservoir, as claimed in claim 1 whereinthe bottom of the selectively spaced interior shear walls are sloped torest on sloped portion of the reservoir bottom which extend upwardlyfrom around the level reservoir bottom portions to the bases of thereservoir side walls and are secured thereto to withstand the resultantforce of the possible horizontal earthquake loads and the existingvertical dead weight loads of the overhead modules of post-tensionedvalley beams and integral domes and the loads of other possible weightscarried by these modules.

3. An enclosed concrete water reservoir, as claimed in claim 2, whereinslight spacing between the shear key structures is selectively filled insome places with elastomer shock pads, so horizontal earthquake loadsoccurring in only one selected direction will be transmitted to theshear walls and surrounding sloping portions of the reservoir bottomalong one side of the reservoir.

4. An enclosed concrete water reservoir, as claimed in claim 2, whereinsome of the spaced columns ae made shorter to carry loads immediatelyadjacent the inside termination of the interior shear walls and betweenthe overhead integral roof modules and sloping portions of the reservoirbottom below, and these shorter columns at their top and bottom portionshave pocket bearing assemblies.

5. An enclosed concrete water reservoir, as claimed in claim 4, whereinthe pocket bearing assemblies, each in turn, comprise, an end elastomerpad, surrounding sleeve elastomer pad, and an encompassing concretestructure to receive the elastomer pads and the respective columnportions.

6. An enclosed concrete water reservoir, as claimed in claim 5, whereinthe encompassing concrete structures at the tops of the shorter columnsare integrally formed with the overhead valley beam, and theencompassing concrete structures at the bottoms of the shorter columnsare integrally formed with both the sloping portions of the reservoirbottom and the respective footings for these shorter columns.

7. An enclosed concrete water reservoir, utilizing a comparative minimumamount of materials, designed to be substantially completely surroundedby earth, the earth above being of sufficient depth for the creation ofscenic and recreational park facilities, inclusive of soil supportingtree growth, comprising:

a. a continuous floor inclusive of footings;

b. surrounding side walls;

c. selectively spaced interior shear walls arranged perpendicular to thesurrounding side walls;

d. spaced columns positioned over the footings;

e. roof modules, integrally formed with posttensioned valley beams alongeach module side fitting in side by side continuous contact with thevalley beams of adjacent roof modules, both laterally andlongitudinally, thereby forming a checkerboard like matrix of modules,supported on the spaced columns and a covering and enclosing dome overeach module, formed by four identical roof portions each extending froma module side, and formed as a part of a cylindrical structure;

f. horizontal cable tendons, used in the posttensioning of the overallarrangement of the roof modules, positioned in conduits in theposttensioned valley beams, and extending through adjacent module valleybeams, forming an orthogonal pattern throughout the checkerboard likematrix of modules;

g. crystallization type coating material to waterproof the concretestructure;

h. compressible sealing materials installed between adjacent concretecomponents of the reservoir to accommodate expansion and contraction ofthe enclosed concrete reservoir during temperature changes andsurrounding earth movements, and to thereby seal the interfaces betweenadjacent concrete components.

8. An enclosed concrete water reservoir, as claimed in claim 7, whereinthe conduits are positioned, before pouring the concrete valley beams,in a parabolic drape configuration, with the high points of the conduitbeing located at the ends of each valley beam over its column supports,and the low point of the conduit being located at the midspan of eachvalley beam.

9. An enclosed concrete water reservoir, as claimed in claim 8, havingsecurement fasteners to hold the cable tendons in place after they havebeen tightened to post tension the valley beam and dome modules in theoverall orthogonal pattern.

10. An enclosed concrete water reservoir, as claimed in claim 9, whereinearth is back filled around the reservoir and distributed over the topof the reservoir,

the column portions.

1. An enclosed concrete water reservoir, utilizing a comparative minimumamount of materials, designed to be substantially completely surroundedby earth, the earth above being of sufficient depth for the creation ofscenic and recreational park facilities, inclusive of soil supportingtree growth, comprising: a. a continuous floor inclusive of footings; b.surrounding side walls; c. spaced columns positioned over the footings;d. post-tensioned valley beams integrally made in molules with integraldomes and supported on the spaced columns; e. horizontal cable tendonsused in the post-tensioning of the overall arrangement of the integralvalley beam and dome molules; and f. selectively spaCed interior shearwalls arranged perpendicular to the surrounding side walls havingcomponents of shear key structures along their tops, and wherein theposttensioned valley beams integrally made in modules with the integraldomes, where such valley beams are located over the interior shearwalls, have components of shear key structures along their bottoms whichcomplementary, with slight spacing, otherwise interfit with the shearkey structures of the interior shear walls; g. compressible sealingmaterials installed between adjacent concrete components of thereservoir to accommodate expansion and contraction of the enclosedconcrete reservoir during both temperature changes and surrounding earthmovements, to thereby seal and keep sealed the interfaces betweenadjacent concrete components.
 2. An enclosed concrete water reservoir,as claimed in claim 1, wherein the bottom of the selectively spacedinterior shear walls are sloped to rest on sloped portion of thereservoir bottom which extend upwardly from around the level reservoirbottom portions to the bases of the reservoir side walls and are securedthereto to withstand the resultant force of the possible horizontalearthquake loads and the existing vertical dead weight loads of theoverhead modules of post-tensioned valley beams and integral domes andthe loads of other possible weights carried by these modules.
 3. Anenclosed concrete water reservoir, as claimed in claim 2, wherein slightspacing between the shear key structures is selectively filled in someplaces with elastomer shock pads, so horizontal earthquake loadsoccurring in only one selected direction will be transmitted to theshear walls and surrounding sloping portions of the reservoir bottomalong one side of the reservoir.
 4. An enclosed concrete waterreservoir, as claimed in claim 2, wherein some of the spaced columns aemade shorter to carry loads immediately adjacent the inside terminationof the interior shear walls and between the overhead integral roofmodules and sloping portions of the reservoir bottom below, and theseshorter columns at their top and bottom portions have pocket bearingassemblies.
 5. An enclosed concrete water reservoir, as claimed in claim4, wherein the pocket bearing assemblies, each in turn, comprise, an endelastomer pad, surrounding sleeve elastomer pad, and an encompassingconcrete structure to receive the elastomer pads and the respectivecolumn portions.
 6. An enclosed concrete water reservoir, as claimed inclaim 5, wherein the encompassing concrete structures at the tops of theshorter columns are integrally formed with the overhead valley beam, andthe encompassing concrete structures at the bottoms of the shortercolumns are integrally formed with both the sloping portions of thereservoir bottom and the respective footings for these shorter columns.7. An enclosed concrete water reservoir, utilizing a comparative minimumamount of materials, designed to be substantially completely surroundedby earth, the earth above being of sufficient depth for the creation ofscenic and recreational park facilities, inclusive of soil supportingtree growth, comprising: a. a continuous floor inclusive of footings; b.surrounding side walls; c. selectively spaced interior shear wallsarranged perpendicular to the surrounding side walls; d. spaced columnspositioned over the footings; e. roof modules, integrally formed withpost-tensioned valley beams along each module side fitting in side byside continuous contact with the valley beams of adjacent roof modules,both laterally and longitudinally, thereby forming a checkerboard likematrix of modules, supported on the spaced columns and a covering andenclosing dome over each module, formed by four identical roof portionseach extending from a module side, and formed as a part of a cylindricalstructure; f. horizontal cable tendons, used in the post-tensioning ofthe overall arrangement of the roof modules, positioned In conduits inthe post-tensioned valley beams, and extending through adjacent modulevalley beams, forming an orthogonal pattern throughout the checkerboardlike matrix of modules; g. crystallization type coating material towaterproof the concrete structure; h. compressible sealing materialsinstalled between adjacent concrete components of the reservoir toaccommodate expansion and contraction of the enclosed concrete reservoirduring temperature changes and surrounding earth movements, and tothereby seal the interfaces between adjacent concrete components.
 8. Anenclosed concrete water reservoir, as claimed in claim 7, wherein theconduits are positioned, before pouring the concrete valley beams, in aparabolic drape configuration, with the high points of the conduit beinglocated at the ends of each valley beam over its column supports, andthe low point of the conduit being located at the midspan of each valleybeam.
 9. An enclosed concrete water reservoir, as claimed in claim 8,having securement fasteners to hold the cable tendons in place afterthey have been tightened to post tension the valley beam and domemodules in the overall orthogonal pattern.
 10. An enclosed concretewater reservoir, as claimed in claim 9, wherein earth is back filledaround the reservoir and distributed over the top of the reservoir, and,thereafter, the area above the reservoir may be prepared for a multipleuse, and tree planting may be undertaken in the soils over the joininglocations of the abutting valley beams.
 11. An enclosed concrete waterreservoir, as claimed in claim 7, wherein selected spaced columns attheir top and bottom portions have pocket bearing assemblies.
 12. Anenclosed concrete water reservoir, as claimed in claim 11, wherein thepocket bearing assemblies, each in turn, comprise, an end elastomer pad,surrounding sleeve elastomer pad, and an encompassing concrete structureto receive the elastomer pads and the column portions.